Safety device for immersion-heaters.



o. s. WALTQN.. SAFETY DEVICE FORv IMMBRSION HBATERS.

A1PL1GATION IILIID'IH` 25, 1911. l v Patented June 6 1911.

.ing off the current.

' 1s provided TED STATES PATENT carica.

cHAnLEsvs. wALToN, or Los ANGELES, cALIFoRNIA.

To all whom it may concer/a:

a citizenof the United States, residing at Los Angeles, in the county of Los Angeles and State of California, have invented a new and useful Safety -Device for Immersion-Heaters, of which the following is -a specification. y

This invention relates to means for safe guarding immersion electric heaters from being burned out by reason of their removal from the liquid to be In the use of immersion heaters it often happens that the party using the same, after having placed the heater in the liquid, removes it from the liquid andvneglects to turn olf the currenttherefrom, with the result'that the-accumulation of heat in the heater causes injury thereto, for example, by burning out the heating element.

A e present invention provides for automaticallybreaking the current to the heater as soon as the heateris removed from the receptacle containing the liquid to be heated. The construction of the device is preferably such that before the heater can be used a switch device must be moved to close the circuit to the heater, said device being maintained in closed position as long as the heater is in operation, butbeing movedto open position automatically when the heater is removed from the liquid.

The accompanying drawings illustrate the invention, and referring thereto Figure 1 is a vertical section. of the heater in operative position within a liquid' containing receptacle. Fig. 2 is a side elevation of the heater in normal or inoperative position, parts of the device being shown in section. Fig. 3 is 'a side elevation at right angles to Fig. 2 of the switch means, the inclosing case therefor being shown in section.'

The heater comprises a heating element indicated at 1 mounted within a casing or body 2 provided with a stem 3, said stem being tubular and containing the leading wires for supplying element.A At the upper end of the stem 3 a switch comprising a movable contact 5 and fixed contacts 6 and 6', said contacts being supported on an insulating head 7 within a switch casing B. Supply wires 9 constituting, for example, an electric cord, are provided for the device, onev Specification of Letters Patent. Application med February 25, 1911.

heated without turn-4 ber 3 to the heating element.

current to the heating derstood that the v Patented June Serial No. 610,947.

l of said wires being connected to said switch.

A member consisting, for example, ofa lever 10 is mounted on the` device in operative relation to the switch and provided with means for engaging a receptacle or vessel 1l containing the liquid to be heated, said lever` or member 10 being normally drawn by spring 12 to position to move the switch aforesaid to open position, and being operated to move the switch to closed position when the device 'is to be used. Spring 12 may be connected to lever 10 and to stem' 3. Lever 10 may be provided with guard means for the guard means onthe lever 10 consisting,

for example, of a U-shaped member 14- adapted to partly embrace and engage the loutside of the receptacle 11 so as to hold the member or lever 10 in extended position, in

which it is distended or separatedr from the stem 3 and the heater body or casing 2, the I spring 12 normally holding said guard means 14 close to the said body 2, as shown in Fig. 2. f

Any suitable form be used, that shown in the drawings being suitable for the quick break, and comprises: an arm 15 of insulating material pivoted' at 15 on the insulating support 7.and carrying the movable contact 5 of the switch, said contact .bridging the two ixed contacts 6, 6. @Conengaging the receptacle 11,.

purpose as it provides forl of switch means may tact 6 is connected to one of thesupply .I

wires 9, and contact'G is connected to a wire 4 leading through the tubular member 3 to the heating element. The other wire 9 extends directly throngh'the tubular mem- A spring 13 connected to arm 15 tends to draw said arm upwardly to open the switch. The lever 10 is pivoted at 10 on the. switch casing 8 and has an arm 16 extending through a' slot 17 in said casing and above the insulating arm 15,- so as to' depress said insu lating arm into position to close the switch when the lever 10 stem 3, as shown in Fig. 1. further provided with a project-ion consisting, for example, of a screw 18 screwed therethrough and extending through an opening 19 in the wall of thecasing v8 to contact with the rear or lower face of the insulating arm 15 to knock or push the switch out of'closed position, it being uncontacts of the switch will close with some friction so as to insure Lever 10 is is movedaway from the" the switch 5, 6, 6.

good contact, and it is necessary to dislodge the same to enable the switch to be opened by the spring 13, said spring operating to open the switch with a quick break as soon as the movable contact 5 has beenpushed from the fixed contacts 6 and 6.

The operation is as follows Normally or when the device is not in use, the lever 10 will be held toward the body of the device by the spring 12, the insulating arm 15 being in elevated position so as to raise the movable contact 5 away from the fixed contacts 6 and 6. Before inserting the heater in the glass or other receptacle containing the liquid to be heated, the lever 10 is operated or pulled away from the body of the heater and in this movement the varm 16 of said lever engages the insulating arm 15, causing the movable contact 5 to be moved into contact with the fixed contacts 6 and 6. Current then passes to theheating element from the wires 9 through The heating element is then placed in the liquid to be heated, the lever 10 being arranged on the outside of the receptacle 11 for such liquid, so that the wall of the said receptacle engages .said' lever or the projection or guard 14: thereon so as to hold the lever in distended position, thereby maintaining the circuit closed as long as the heater is kept in the receptacle.

-As soon as the heater is removed from the` receptacle, the spring 12 throws the lever to collapsed or folded position, causing the projection 18 to engage the insulating arm 15 of the switch, and throws said switch open, the opening movement being quickly completed by the spring 13 so as to break the arc.

What I claim is 1. In combination with an electric immersion heater, a switch controlling the circuit thereof, and means movably mounted en said heater and controlling said switch, said controlling means having a portion extending alongside the heater to engage the wall of a receptacle lin which the heater is placed.

2. In combination with an electric im- `mersion heater, a .switch controlling the vthe receptacle in which the heater is to be immersed to hold the switch in closed position, and means tending to move the switch to open position.

4. In combination with an electric immersion heater, a switch controllin the circuit thereof, and means for contro ing said switch movably mounted on said heater and engagin the receptacle when the heater is placed tv erein, said controllin means bemg thereby maintained in a enite position relative to the heater.

In testimony whereof, I have hereunto set my hand at Los Angeles, California, this 18th day of February, 1911.

` CHARLES S. WALTON. In presence of ARTHUR P. KNIGHT,

FRANK L. A. GRAHAM.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of ?a.tents, Washington, D. 0.? 

